Duplicate sketch can
be used to save time if you only want to minimally change the original
sketch, for example.
In the
context menu, call the command Duplicate sketch.
-> The
Sketcher with the duplicated sketch opens.
Modify the
values in the Change parameter
dialog.
Extrude the
duplicated sketch in opposite direction this time. In this example
with disabled option Opposite direction. Before the option had been enabled.